Line Set for Mini Split Air Conditioner (1/4&rdquo; X 1/2") - Typically used 12,000/18,000 BTU systems - All Copper (16 Ft) with Insulation - Flared Fittings Standard Size 1/4" x 1/2" - Commonly used for 12,000 and 18,000 BTU Mini-Split A/Cs (Please check with your system to confirm size needed) 16 Feet High Quality Copper Line with Insulation Easy Connect - Flare Copper Nut Fittings